Substrate having thermal management coating for an insulating glass unit

ABSTRACT

A coated article is provided for use in an IG unit. The article includes a substrate and a coating formed over at least a portion of the substrate. The coating includes a plurality of separation layers having one or more dielectric layers and a plurality of infrared reflective layers. The coating can be positioned on the #2 or #3 surface of the IG unit and can provide a reference solar heat gain coefficient of less than or equal to 0.35.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefits of U.S. ProvisionalApplication Serial No. 60/377,783 filed May 3, 2002, which is hereinincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to solar control coatings and,more particularly, to a coating that has solar control and spectralproperties adaptable for use on a surface other than the inner surfaceof the outboard sheet (#2 surface) of a multi sheet-glazed insulatingunit.

[0004] 2. Description of the Currently Available Technology

[0005] Multi sheet-glazed insulating glass units (“IG units”) having twoor more spaced glass sheets are becoming the industry standard forresidential and commercial architecture in geographic regions havingcool to cold climates, e.g., those climates characterized by seasonsrequiring extensive periods of operating heating furnaces. The IG unithas improved thermal insulating performance over windows having singleglass sheets due to its reduced conductive and convective transfer ofheat compared to a conventional window. However, until fairly recently,the use of IG units has not been popular in geographic regions havingwarm to hot climates, e.g., those climates characterized by seasonsrequiring extensive periods of operating air conditioners, because theprimary functionality required of windows in such regions is solar heatload reduction, not insulating value.

[0006] During the past several decades, solar-control coated glasseshave been introduced into the market. Such solar-control coated glassesachieve significant levels of solar heat load reduction by decreasingthe amount of solar energy (in the visible and/or near-infrared portionsof the electromagnetic spectrum) that is directly transmitted throughthe coated glass, often by absorbing large amounts of the incidentenergy and/or by reflecting large amounts of visible light. Morerecently, certain high-performance silver-based low emissivity (low-E)coatings have been recognized as also having a significant degree ofsolar-control functionality in addition to their excellent thermalinsulating properties. Such silver-based solar-control/low-E coatedglasses are now becoming increasingly popular not only in climatescharacterized by long heating seasons (for their low-E/thermalinsulating performance) but also in climates characterized by longcooling seasons such as the deep South, Southeastern, and Southwesternparts of the United States due to their solar-control benefits.

[0007] Today, the glazing industry desires to have window systems thathave additional functionalities over and beyond thermal insulationand/or solar-control benefits (hereinafter referred to as “thermalmanagement functionalities”). Examples of other such desiredfunctionalities include aesthetics, safety, and ease of cleaning. Forexample, architects may desire to provide a wide range of colors for anIG unit to enhance the aesthetic appearance of a building. To achievethis goal, colored or tinted glass sheets can be used as the outersheets of the IG unit. A solar control coating can be deposited on theinner surface of the outer tinted glass sheet (#2 surface of the IGunit) to provide solar control properties. An example of one suitablesolar control coating is sold by PPG Industries, Inc. under theregistered trademark Solarban® 60. The Solarban® 60 coating, whichincludes two infrared-reflecting films of silver, is discussed in U.S.Pat. No. 5,821,001.

[0008] While this standard practice of forming a solar control coatingon the inner surface of the tinted glass sheet (#2 surface of the IGUnit) does provide acceptable IG units, there are some drawbacks tocoating tinted glass sheets. For example, tinted glass is generally notmade as often as clear glass and, therefore, may not be as readilyavailable for coating if an architect desires a particular color for anouter pane of an IG unit in a short period of time. Moreover, if tintedglass is stockpiled in anticipation of coating, the tinted glass candevelop surface deterioration or corrosion during storage. Suchcorrosion may not be apparent until after the tinted glass is coated andcan make the coating appear mottled, stained, or otherwise unacceptable.

[0009] One technique to address the above-discussed drawbacks is toapply the solar control coating to an inner pane of a double glazed IGunit with an outer pane of an uncoated tinted glass sheet. U.S. Pat. No.5,059,458 discloses a double glazed IG unit having an outer tinted glasssheet and an inner clear glass sheet having a silver layer on the outersurface of the clear glass sheet. However, this approach also has somedrawbacks. For example, using a conventional solar control coating onthe #3 surface of an IG unit (the outer surface of the inner glass sheetof a two pane IG unit) provides different solar-control performance ofthe overall IG unit than having the coating on the #2 surface of the IGunit (all other factors remaining the same). Specifically, putting thesolar control coating on the #3 surface rather than the #2 surfaceresults in a relative increase in the shading coefficient and a relativeincrease in the solar heat gain coefficient.

[0010] For example, for a reference IG unit (defined below), aconventional Solarban® 60 coating on the #2 surface can result in aluminous transmittance of 60%, a luminous exterior reflectance of 9% to10%, a shading coefficient (ASHRAE summer conditions) of 0.35 to 0.36,and a solar heat gain coefficient (ASHRAE summer conditions) of 0.30 to0.31. Switching the Solarban® 60 coating to the #3 surface changes theIG unit performance to a luminous transmittance of 60%, a luminousexterior reflectance of 11%, a shading coefficient (ASHRAE summerconditions) of 0.41, and a solar heat gain coefficient (ASHRAE summerconditions) of 0.36.

[0011] The performance of the Solarban® 60 coating has been wellreceived in the IG unit field. Therefore, it would be advantageous toprovide a coating, e.g., a solar control coating, that could be utilizedon a surface of an inner pane of an IG unit (e.g., the #3 surface of atwo pane IG unit) that provides similar solar control and/or aestheticcharacteristics as those of the Solarban® 60 coating on the #2 surfaceof the IG unit to address at least some of the problems discussed above.

SUMMARY OF THE INVENTION

[0012] One embodiment of the present invention is a coating on clearglass which would be glazed in the inboard position of a double-glazedIG unit with the coating on the #3 surface such that, when combined withan uncoated tinted or clear outboard light (pane) in the IG unit, the IGunit has aesthetics and thermal management performance that are similarif not identical to IG units fabricated using a conventional solarcontrol coating on the #2 surface of a clear or tinted glass sheet,respectively. As can be appreciated, the invention is not limitedthereto. More particularly and not limiting to the invention, the coatedclear glass substrates of the present invention can be used as anoutboard light of an IG unit (i.e. with the thermal management coatingof the invention in the #2 surface orientation) if the resultantaesthetics and thermal-management performance of such an IG unitconfiguration are acceptable for the particular use.

[0013] A coated article for use in an IG unit comprises a substrate anda coating formed over at least a portion of the substrate. The coatingcan comprise a first separation layer comprising at least one firstdielectric layer; a first infrared reflective layer deposited over thefirst separation layer; a second separation layer comprising at leastone dielectric layer deposited over the first infrared reflective layer;a second infrared reflective layer deposited over the second separationlayer; a third separation layer comprising at least one dielectric layerdeposited over the second infrared reflective layer; and a thirdinfrared reflective layer deposited over the third separation. Thecoating can be positioned on the #2 or #3 surface of the IG unit afterbeing mounted.

[0014] Another coated article for use in an IG unit can comprise asubstrate and a coating formed over at least a portion of the substrate.The coating can comprise a first separation layer comprising at leastone dielectric layer; a first infrared reflective layer formed over thefirst separation layer; a second separation layer comprising at leastone dielectric layer formed over the first infrared reflective layer;and a second infrared reflective layer formed over the second separationlayer. The coating can be positioned on the #2 or #3 surface of the IGunit after being mounted. The coating can provide a reference solar heatgain coefficient of less than or equal to 0.35.

[0015] An IG unit comprises a first pane defining a #1 and a #2 surface,at least one second pane defining a #3 and a #4 surface, and a coatingformed over at least a portion of the #2 or #3 surface. The coating cancomprise a first separation layer comprising at least one firstdielectric layer; a first infrared reflective layer deposited over thefirst separation layer; a second separation layer comprising at leastone dielectric layer deposited over the first infrared reflective layer;a second infrared reflective layer deposited over the second separationlayer; a third separation layer comprising at least one dielectric layerdeposited over the second infrared reflective layer; and a thirdinfrared reflective layer deposited over the third separation layer.

[0016] Another IG unit comprises a first pane defining a #1 and a #2surface, at least one second pane defining a #3 and a #4 surface, and acoating formed over at least a portion of the #2 or #3 surface. Thecoating can comprise a first separation layer comprising at least onefirst dielectric layer; a first infrared reflective layer deposited overthe first separation layer; a second separation layer comprising atleast one dielectric layer deposited over the first infrared reflectivelayer; and a second infrared reflective layer deposited over the secondseparation layer. The coating can provide a reference solar heat gaincoefficient of less than or equal to 0.35.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a side, sectional view (not to scale) of a coatedarticle incorporating features of the invention; and

[0018]FIG. 2 is a side, sectional view (not to scale) of an IG unitincorporating features of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] As used herein, spatial or directional terms, such as “left”,“right”, “inner”, “outer”, “above”, “below”, “top”, “bottom”, and thelike, relate to the invention as it is shown in the drawing figures.However, it is to be understood that the invention may assume variousalternative orientations and, accordingly, such terms are not to beconsidered as limiting. Further, as used herein, all numbers expressingdimensions, physical characteristics, processing parameters, quantitiesof ingredients, reaction conditions, and the like, used in thespecification and claims are to be understood as being modified in allinstances by the term “about”. Accordingly, unless indicated to thecontrary, the numerical values set forth in the following specificationand claims may vary depending upon the desired properties sought to beobtained by the present invention. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical value should at least be construedin light of the number of reported significant digits and by applyingordinary rounding techniques. Moreover, all ranges disclosed herein areto be understood to encompass the beginning and ending range values andany and all subranges subsumed therein. For example, a stated range of“1 to 10” should be considered to include any and all subranges between(and inclusive of) the minimum value of 1 and the maximum value of 10;that is, all subranges beginning with a minimum value of 1 or more andending with a maximum value of 10 or less, e.g., 5.5 to 10. The terms“formed over”, “deposited over”, or “provided over” mean formed,deposited, or provided on but not necessarily in contact with thesurface. For example, a coating layer “formed over” a substrate does notpreclude the presence of one or more other coating layers or films ofthe same or different composition located between the formed coatinglayer and the substrate. All documents referred to herein are to beunderstood to be incorporated by reference in their entirety. Unlessindicated otherwise, the “luminous” or “visible” region is in thewavelength range of 380 nanometers (nm) to 780 nm, the “infrared” (IR)region is in the wavelength range of 780 nm to 100,000 nm, and the“ultraviolet” (UV) region is in the wavelength range of 300 nm up to 380nm. The term “optical thickness” means the product of a material'srefractive index (dimensionless), referenced to about 550 nanometers(nm) in the visible region of the electromagnetic spectrum, times itsphysical thickness in Angstroms (A). As used herein, the term “solarcontrol coating” refers to a coating that affects the solar propertiesof the coated article, such as but not limited to shading coefficientand/or emissivity and/or the amount of solar radiation reflected byand/or absorbed by and/or transmitted through the coated article, e.g.,infrared or ultraviolet absorption or reflection. A solar controlcoating can block, absorb, or filter selected portions of the solarspectrum, such as but not limited to the visible spectrum.

[0020] An exemplary coating will first be described and then the use ofthe coating in a double pane IG unit will be described. However, it isto be understood that the invention is not limited to use with doublepane IG units but could be practiced, for example, with single panewindows or multipane IG units having three or more panes.

[0021] With reference to FIG. 1, there is shown an exemplary coatedarticle 10 incorporating features of the invention. The coated article10 includes a substrate 12 having a coating 14.

[0022] In the broad practice of the invention, the substrate 12 can beof any desired material having any desired characteristics, such asopaque, translucent, or transparent to visible light. By “transparent”is meant having visible light transmittance through the substrate ofgreater than 0% up to 100%. Alternatively, the substrate can betranslucent or opaque. By “translucent” is meant allowingelectromagnetic energy (e.g., visible light) to pass through thesubstrate but diffusing this energy such that objects on the side of thesubstrate opposite to the viewer are not clearly visible. By “opaque” ismeant having a visible light transmittance of 0%. Examples of suitablesubstrates include, but are not limited to, plastic substrates (such asacrylic polymers, such as polyacrylates; polyalkylmethacrylates, such aspolymethylmethacrylates, polyethylmethacrylates,polypropylmethacrylates, and the like; polyurethanes; polycarbonates;polyalkylterephthalates, such as polyethyleneterephthalate (PET),polypropyleneterephthalates, polybutyleneterephthalates, and the like;polysiloxane containing polymers; or copolymers of any monomers forpreparing these, or any mixtures thereof); metal substrates, such as butnot limited to galvanized steel, stainless steel, and aluminum; ceramicsubstrates; tile substrates; glass substrates; or mixtures orcombinations of any of the above. For example, the substrate can beconventional untinted soda-lime-silica-glass, i.e., “clear glass”, orcan be tinted or otherwise colored glass, borosilicate glass, leadedglass, tempered, untempered, annealed, or heat-strengthened glass. Theglass may be of any type, such as conventional float glass or flatglass, and may be of any composition having any optical properties,e.g., any value of visible radiation transmission, ultraviolet radiationtransmission, infrared radiation transmission, and/or total solar energytransmission. Types of glass suitable for the practice of the inventionare described in, but are not to be considered as limited to, U.S. Pat.Nos. 4,746,347; 4,792,536; 5,240,886; 5,385,872; and 5,393,593. Further,the substrate can be a clear plastic and/or polymeric substrate with acoating of the invention deposited on the substrate's surface. Inaddition, the coating stack of the invention can be applied to apolymeric or plastic “web” or thin sheet that can be suspended inside anUG unit as is known in the art. In the latter case, the coated web wouldprovide the dominant portion of the thermal-management benefits and thethermal-management coating would be on a substrate other than the glassor plastic substrates that comprise the primary boundary surfaces of theIG unit.

[0023] The exemplary coating 14 can be a multilayer coating stack. Theterms “coating stack” or “coating” can include one or more layers and a“layer” can include one or more films. With reference to FIG. 1, theillustrated exemplary coating 14 includes three infrared reflectivelayers 16, 18 and 20. For ease of discussion the layer 16 is referred toas the first infrared reflective layer; the layer 18 is referred to asthe second infrared reflective layer, and the layer 20 is referred to asthe third (optional) infrared reflective layer. The illustrated coating14 further includes separation layers 22, 24, 26 and 28. The separationlayer 22 or first separation layer is between the substrate 12 and thefirst infrared reflective layer 16; the separation layer 24 or secondseparation layer is between the first infrared reflective layer 16 andthe second infrared reflective layer 18; the separation layer 26 orthird separation layer is between the second infrared reflective layer18 and the third infrared reflective layer 20, and the fourth separationlayer or outermost separation layer) 28 is between the third infraredreflective layer 20 and the environment. As can be appreciated by thoseskilled in the art, the invention contemplates more than three infraredreflective layers and more than four separation layers. Further, as willbe noted below, the invention also contemplates less than three infraredreflective layers and less than four separation layers.

[0024] The coating 14 of the invention can be deposited over thesubstrate 12 by any conventional method, such as but not limited tospray pyrolysis, chemical vapor deposition (CVD), sol-gel, electron beamevaporation, or magnetron sputter vapor deposition (MSVD). In oneembodiment, the coating 14 is deposited by MSVD.

[0025] The first separation layer 22 can include one or more dielectric(e.g., antireflective) layers or films and optionally one or morenon-dielectric layers or films. As used herein a “non-dielectric layeror film” is a material that has mobile carriers of electric charge, suchas metals, semiconductors, semimetals, alloys, mixtures, or combinationsthereof. The dielectric layers or films can be any of the types known inthe art, such as but not limited to, oxides, nitrides, and/oroxynitrides, such as but not limited to zinc oxide, zinc stannate,silicon nitride, silicon-aluminum nitride, ceramics, titanium dioxide,and/or of the types disclosed in U.S. Pat. Nos. 5,821,001 and 5,942,338.The dielectric films can function to (1) provide a nucleation layer foroverlying layers and/or films subsequently deposited, e.g., asubsequently deposited infrared reflective layer, and/or (2) to allowsome control over the aesthetics and thermal-management performance ofthe coatings. The dielectric films can each include different dielectricmaterials with similar refractive indices or different materials withdifferent refractive indices. The relative proportions of the dielectricfilms of the separation layers can be varied to optimizethermal-management performance, aesthetics, and/or durability of thecoated article. Furthermore, any or all of the dielectric films of theseparation layers can exhibit optical absorption in any region of theelectromagnetic spectrum.

[0026] The non-dielectric layers or film(s) of the first separationlayer (or subsequent separation layers) can be any of the types known inthe art, such as but not limited to, titanium, copper, stainless steel,and can function (1) to protect the underlying films from damage and/ordegradation during heat-treatment of the coated glass for those productsdesigned and/or intended to be subjected to high-temperature processingafter being coated, and/or (2) to enhance mechanical and/or chemicaldurability of the coated article's thin film optical stack, and/or (3)to contribute to and allow some control over the aesthetics and/orthermal-management performance of the coated article, e.g., byabsorption. Any or all of the non-dielectric films can exhibit opticalabsorption in any region of the electromagnetic spectrum. The inventioncontemplates using the non-dielectric films of the separation layersover, under, and/or between the dielectric films(s). For example, butnot limiting to the invention, non-dielectric films that can be used foroptical absorption can be deposited on the substrate, between thedielectric films, or over the last deposited dielectric film of thefirst separation layer.

[0027] The first separation layer 22 can be a substantially single phaselayer or film, such as a metal alloy oxide layer, e.g., zinc stannate ora mixture of phases composed of zinc and tin oxides, or can be composedof a plurality of layers or films, e.g., metal oxide films, such asthose disclosed in U.S. Pat. Nos. 5,821,001; 4,898,789; and 4,898,790.In one embodiment, the first separation layer 22 comprises a multi-layerstructure having a first metal oxide or alloy oxide layer or film (firstdielectric layer) deposited over at least a portion of a major surfaceof the substrate 12 and a second metal oxide layer or film (seconddielectric layer) deposited over at least a portion of the first metalalloy oxide film. In one embodiment, the first metal alloy oxide layercan be an oxide mixture or alloy oxide of zinc and tin. For example, thezinc/tin alloy can comprise zinc and tin in proportions of 10 wt. % to90 wt. % zinc and 90 wt. % to 10 wt. % tin. One suitable metal alloyoxide for use in the invention is zinc stannate. The second metal oxidelayer can comprise a zinc containing layer, such as zinc oxide. In oneembodiment, the first metal alloy oxide layer can comprise an oxide ofzinc and tin, e.g., zinc stannate, and can have a thickness in the rangeof 100 Angstroms (Å) to 500 Å, such as 150 Å to 400 Å, e.g., 200 Å to350 Å, e.g., 250 Å to 350 Å. The second metal oxide layer can comprisezinc oxide and can have a thickness in the range of 50 Å to 200 Å, suchas 75 Å to 150 Å, e.g., such as 100 Å to 150 Å, such as 130 Å to 160 Å.

[0028] In one embodiment, although not limiting to the invention, thetotal physical thickness of the dielectric film(s) of the firstseparation layer 22 can be in the range of 50 Å to 700 Å, such as in therange of 100 Å to 600 Å, such as in the range of 200 Å to 575 Å, such as293 Å to 494 Å. The total physical thickness of the non-dielectricfilm(s) can be in the range of 0 Å to 500 Å, such as 0 Å to 400 Å, suchas 0 Å to 300 Å, such as 0 Å to 50 Å, such as 0 Å to 30 Å. The firstseparation layer 22 can have a total physical thickness in the range of50 Å to 1200 Å, such as in the range of 100 Å to 1000 Å, such as in therange of 200 Å to 875 Å, such as in the range of 250 Å to 500 Å.

[0029] The first infrared (IR)-reflective layer 16 can be deposited overthe first separation layer 22 and can have a high reflectivity in theinfrared (solar-infrared and/or thermal-infrared) portion of theelectromagnetic spectrum, e.g., but not limiting to the invention,greater than 50%. The first infrared-reflective layer 16 can include oneor more films of infrared-reflective materials, such as but not limitedto, gold, copper, silver, or mixtures, alloys, or combinations thereof.In one embodiment of the invention, the first infrared reflective layer16 comprises silver. The films can exhibit some reflectivity in thevisible light portion of the electromagnetic spectrum. The firstIR-reflective layer 16 (as well as the other IR-reflective layers) can(1) provide rejection of solar-infrared radiation and/or visible lightto help control solar heat gain through the window and/or to controlglare due to transmitted visible light; (2) when the infrared-reflectivelayer exhibits appreciable reflectivity in the thermal infrared portionof the electromagnetic spectrum e.g., but not limiting thereto greaterthan 50%, to impart some low-emissivity characteristics, e.g., but notlimiting to the invention, an emissivity less than 0.25 to the coatedarticle to inhibit radiative heat transfer across and/or through the IGunit, and/or (3) allow some control over the aesthetics of the coatedarticle. Furthermore, any or all of the films of the infrared-reflectivelayers can exhibit optical absorption in any region of theelectromagnetic spectrum.

[0030] In one embodiment, although not limiting to the invention, thethickness of the first infrared-reflective layer can be in the range of5 Å to 200 Å, such as 10 Å to 200 Å, such as 50 Å to 200 Å, such as 75 Åto 175 Å, such as 75 Å to 150 Å, such as 93 Å to 109 Å. In oneparticular embodiment, the first infrared-reflective layer includessilver and has a thickness in the range of 100 Å to 150 Å, such as 110 Åto 140 Å, such as 120 Å to 130 Å.

[0031] Further, in the practice of the invention, when an additionalinfrared reflective layer, e.g. the second infrared-reflective layer 18,is to be provided, the second separation layer 24 can be provided.Otherwise, the outermost separation layer 28 discussed in detail belowis applied over the first infra-red reflective layer 16.

[0032] The second separation layer 24 can be deposited over the firstinfrared-reflective layer 16 and can include one or more dielectriclayers or films and/or one or more non-dielectric layers or films. Ascan be appreciated the dielectric layers or films and the non-dielectriclayers or films of the second separation layer can be similar to ordifferent than the material and number of the dielectric films and/ornon-dielectric films of the first separation layer 22. In one practice,a non-dielectric film (“first non-dielectric film(s) of the secondseparation layer”) can be deposited over the first IR reflective film16. The first non-dielectric film can be a metal, such as but notlimited to, titanium and is often referred to in the art as a “primerfilm” or “barrier film”. The first non-dielectric film(s) of the secondseparation layer can (1) protect the underlying infrared-reflectivelayer from degradation (e.g. oxidation and/or plasma-induced damage)during: (A) deposition of overlying films, e.g., dielectric films of thesecond separation layer 24; and/or (B) heat-treatment of the coatedarticle for those products that are designed/intended to be subjected tohigh-temperature processing after being coated; and/or (2) to contributeto and allow some control of the aesthetics and/or thermal-managementperformance of the coated article. The first non-dielectric film(s) ofthe second separation layer 24 can exhibit optical absorption in anyregion of the electromagnetic spectrum, if desired. Types ofnon-dielectric films that can be used in the practice of the inventioninclude, but one not limited to, those disclosed in PCT/US00/15576.

[0033] One or more dielectric layers or films can be deposited over thefirst non-dielectric film(s) of the second separation layer 24, ifpresent, otherwise over the first infrared-reflective layer 16. Thedielectric films(s) of the second separation layer 24 can include one,two, or more films with similar refractive indices in a similar fashionas described for the dielectric films of the first separation layer 22.Furthermore, any or all of the dielectric films of the second separationlayer 24 can exhibit optical absorption in any region of theelectromagnetic spectrum. It is also believed that the dielectricfilm(s) of the second separation layer 24 provides some protection ofthe underlying layers and/or films from mechanical damage and/orchemical/environmental attack, degradation, or corrosion.

[0034] Optionally the second separation layer 24 can include othernon-dielectric layers or film(s) (“other non-dielectric film(s) of thesecond separation layer”) over, under or between the dielectric film(s)of the second separation layer 24. The other non-dielectric film(s) ofthe second separation layer 24 can be the same as and/or differentmaterial and number than the non-dielectric film(s) of the firstseparation layer 22. The relative proportions of the component films ofthe second separation layer 24 can be varied in order to optimizethermal-management performance, aesthetics, and/or chemical/mechanicaldurability of the coated article.

[0035] In one practice of the invention, although not limiting thereto,the first non-dielectric film(s) of the second separation layer can havea thickness in the range of 0 Å to 100 Å, such as 5 Å to 75 Å, such as 5Å to 50 Å, such as 5 Å to 30 Å, such as 15 Å to 25 Å. In one particularembodiment, the first non-dielectric film can have a thickness in therange of 5 Å to 15 Å, such as 10 Å to 25 Å. If present, the othernon-dielectric film(s) of the second separation layer 24 can have athickness in the range of 0 Å to 500 Å, such as 0 Å to 400 Å, such as 0Å to 300 Å.

[0036] The dielectric layers or film(s) of the second separation layer24 can be in the range of 600 Å to 1000 Å, such as in the range of 700 Åto 900 Å, such as in the range of 725 Å to 875 Å, such as 739 Å to 852Å. For example, the second separation layer 24 can have a thickness inthe range of 600 Å to 1500 Å, such as in the range of 705 Å to 1375 Å,such as in the range of 730 Å to 1250 Å, such as 730 Å to 1230 Å. In oneparticular embodiment, the second separation layer 24 can be amultilayer structure having one or more metal oxide or metal alloy oxidelayers or films, such as those described above with respect to the firstseparation layer 22. In one embodiment, the second separation layer 24has a first metal oxide layer or film, e.g., a zinc oxide layer,deposited over the first primer film (first non-dielectric layer). Asecond metal alloy oxide layer or film, e.g., a zinc stannate layer, canbe deposited over the first zinc oxide layer. A third metal oxide layer,e.g., another zinc oxide layer, can be deposited over the zinc stannatelayer to form a multi-film second separation layer 24. In one particularembodiment, the first and third metal oxide layers of the secondseparation layer 24 can have a thickness in the range of 50 Å to 200 Å,e.g., 75 Å to 150 Å, e.g., 100 Å to 120 Å, e.g., 110 Å to 120 Å. Thesecond metal alloy oxide layer can have a thickness in the range of 100Å to 500 Å, e.g., 200 Å to 500 Å, e.g., 300 Å to 500 Å, e.g., 400 Å to500 Å, e.g., 450 Å to 500 Å.

[0037] The second infrared-reflective (IR) layer 18 can be depositedover the second separation layer 24 and can include one or more films ofinfrared-reflective materials of the type referred to above for thefirst infrared-reflective layer 16. As can be appreciated the materialsof the second infrared reflective layer can be the same or differentthan the materials of the first infrared reflective layer.

[0038] In one practice of the invention, although not limiting thereto,the thickness of the second infrared-reflecting layer can be in therange of 50 Å to 250 Å, such as 75 Å to 225 Å, such as 75 Å to 200 Å,such as 120 Å to 150 Å, such as 130 Å to 150 Å, such as 114 Å to 197 Å.

[0039] In the practice of the invention, when an additional infraredreflective layer, e.g., the third infrared-reflective layer 20, is to beprovided in the coating 14, the third separation layer 26 is provided;otherwise the outermost separation layer 28 discussed in detail belowcan be applied over the second infrared-reflecting layer 18.

[0040] The third separation layer 26 can be deposited over the secondinfrared-reflective layer 18 and can include one or more dielectriclayers or films and/or one or more non-dielectric layers or films, suchas those described above. As can be appreciated, the dielectric filmsand the non-dielectric films of the third separation layer 26 can besimilar to or different than the material and number of the dielectricfilms and/or non-dielectric films of the first and/or second separationlayers 22, 24. In one practice of the invention, although not limitingthereto, the first non-dielectric film(s) of the third separation layer26 can have a thickness in the range of 0 Å to 100 Å, such as 5 Å to 75Å, such as 5 Å to 50 Å, such as 5 Å to 30 Å, such as 15 Å to 25 Å. Inone particular embodiment, the first non-dielectric film can have athickness in the range of 5 Å to 15 Å, such as 10 Å to 25 Å. If present,the other non-dielectric film(s) of the third separation layer 26 canhave a thickness in the range of 0 Å to 500 Å, such as 0 Å to 400 Å,such as 0 Å to 300 Å.

[0041] One or more dielectric layers or films can be deposited over thefirst non-dielectric film(s) of the third separation layer 26, ifpresent, otherwise over the second infrared-reflective layer 18. Therelative proportions of the component films of the third separationlayer may be varied in order to optimize thermal-management performance,aesthetics, and/or chemical/mechanical durability of the coated article.

[0042] In one embodiment, the dielectric film(s) of the third separationlayer 26 can be in the range of 600 Å to 1000 Å, such as 625 Å to 900 Å,such as 650 Å to 875 Å, such as 729 Å to 764 Å. The third separationlayer 26 can have a thickness in the range of 600 Å to 1600 Å, such as630 Å to 1375 Å, such as 755 Å to 1250 Å, such as 730 Å to 1230 Å. Inone embodiment, the third separation 26 can be a multi-layer structuresimilar to the second separation layer. For example, the thirdseparation layer 26 can include a first metal oxide layer, e.g., a zincoxide layer, a second metal alloy oxide layer, e.g., a zinc stannatelayer over the first zinc oxide layer, and a third metal oxide layer,e.g., another zinc oxide layer, deposited over the zinc stannate layer.In one non-limiting embodiment, the first and third metal oxide layerscan have thicknesses in the range of 50 Å to 200 Å, such as 75 Å to 150Å, e.g., 100 Å to 120 Å, e.g., 100 Å. The metal alloy oxide layer canhave a thickness in the range of 100 Å to 1,000 Å, e.g., 200 Å to 800 Å,e.g., 300 Å to 600 Å, e.g., 500 Å.

[0043] The third infrared-reflective (IR) layer 20 can be deposited overthe third separation layer 26 and can include one or more films ofinfrared-reflective materials of the type referred to in the discussionregarding the first and/or second infrared-reflective layers 16,18,respectively. As can be appreciated the material(s) of the thirdinfrared reflective layer 20 can be the same or different than thematerial(s) of the first and/or second infrared reflective layers 16,18.

[0044] In one practice of the invention, although not limiting thereto,the thickness of the third infrared-reflecting layer 20 can be in therange of 50 Å to 250 Å, such as 75 Å to 225 Å, such as 75 Å to 200 Å,such as 140 to 180 Å, such as 150 to 170 Å, such as 160 to 170 Å, suchas 138 Å to 181 Å.

[0045] Further, in the practice of the invention, when an additionalinfrared reflective layer, e.g. a fourth infrared-reflective layer (notshown) similar to the first, second and/or third infrared-reflectinglayers 16, 18 and 20, respectively, is to be provided in the coating 14,an additional separation layer (not shown) similar to the second and/orthird separation layers 24 and 26, respectively, can be provided.Otherwise, the fourth or outermost separation layer 28 discussed indetail below can be applied over the third infrared-reflecting layer 16.

[0046] The outermost separation layer 28 can be deposited over the thirdinfrared-reflective layer 20 and can include one or more dielectriclayers or films and/or one or more non-dielectric layers or films. Ascan be appreciated the dielectric films and the non-dielectric films ofthe outermost separation layer can be similar to or different than thematerials and number of the dielectric films and/or non-dielectric filmsof the first, second, and/or third separation layers 22, 24 and 26,respectively. In one practice, a first primer film or firstnon-dielectric film(s) of the outermost separation layer, such astitanium, can be deposited over the underlying infrared reflectivelayer, e.g. the third infrared-reflective layer 20. In one particularembodiment, the thickness of the first non-dielectric film(s) of theoutermost separation layer can be in the range of 0 Å to 100 Å, such as5 Å to 75 Å, such as 5 Å to 50 Å, such as 5 Å to 30 Å, such as 5 Å to 15Å, such as 10 Å to 20 Å, such as 15 Å to 25 Å. If present, the othernon-dielectric film(s) of the outermost separation layer 28 can have athickness in the range of 0 Å to 500 Å, such as 0 Å to 400 Å, such as 0Å to 300 Å.

[0047] One or more dielectric layers or films and one or more protectivefilms can be deposited over the first non-dielectric film(s) of theoutermost separation layer 28, if present, otherwise over the thirdinfrared-reflective layer 20. The relative proportions of the componentfilms of the outermost separation layer 28 can be varied in order tooptimize thermal-management performance, aesthetics, and/orchemical/mechanical durability of the coated article. In one practice,the outermost separation layer 28 can have a thickness in the range of170 Å to 600 Å, such as in the range of 205 Å to 500 Å, such as in therange of 235 Å to 430 Å. The thickness of any temporary overcoat(described below) is not included because it is removed before theproduct is used.

[0048] The dielectric film(s) of the outermost separation layer can bein the range of 100 Å to 400 Å, such as in the range of 150 Å to 350 Å,such as in the range of 175 Å to 325 Å, such as 206 Å to 310 Å. Theoutermost separation layer 28, excluding the protective film(s), canhave a thickness in the range of 100 Å to 1000 Å, such as in the rangeof 155 Å to 725 Å, such as in the range of 180 Å to 675 Å, such as 185 Åto 705 Å. In one embodiment, the outermost separation layer 28 can becomprised of one or more metal oxide or metal alloy oxide containinglayers or films such as those discussed above with respect to the first,second, or separation layers. In one embodiment, the outermostseparation layer 28 is a multi-film layer having a first metal oxidelayer or film, e.g., a zinc oxide layer or film, deposited over thethird primer film and a second metal alloy oxide layer or film, e.g., azinc stannate layer or film, deposited over the zinc oxide layer orfilm. The metal oxide layer or film can have a thickness in the range of25 Å to 200 Å, such as 50 Å to 150 Å, such as 100 Å. The metal alloyoxide film can have a thickness in the range of 25 Å to 500 Å, e.g., 50Å to 250 Å, e.g., 100 Å to 210 Å.

[0049] A permanent protective overcoat can be deposited over theoutermost separation layer 28 to provide protection against mechanicaland chemical attack. In one embodiment, the protective overcoat can be ametal oxide, such as titanium dioxide or zirconium oxide, having athickness in the range of about 10 Å to 100 Å, e.g., 20 Å to 60 Å, e.g.,30 Å to 40 Å, such as 30 Å to 46 Å.

[0050] The inclusion of protective films as components of the outermostseparation layer 28 is optional. The protective film(s) can protect theunderlying layers from mechanical damage and/or chemical attack due toenvironmental exposure during storage, shipment, and processing of thecoated article. The protective film(s) can also contribute to theaesthetics and/or thermal-management performance of the coated article.The protective film(s) can be one, two, or more films with similarrefractive indices. Furthermore, any or all of the protective films canexhibit optical absorption in any region of the electromagneticspectrum, if desired. The protective films can be of the durable type,which provide mechanical and chemical protection and remain on theoutermost surface of the coating. These types of protective films aredisclosed in U.S. Pat. No. 4,786,563. The protective films can be of theless durable type, e.g. zinc oxide.

[0051] Still further, a temporary protective film, such as commerciallyavailable fro PPG Industries, Inc. and identified by the trademark “TPO”and described in U.S. Patent Application Nos. 60/142,090 and 09/567,934can be deposited over the permanent protective overcoat. The function ofthe temporary protective film is to provide additional protection of theunderlying layers from mechanical damage during packaging, shipment, anddownstream processing (e.g. unpacking, unloading, cutting,seaming/edging, edge deletion of the MSVD coating, and/or washing) ofthe coated article. The temporary film can be applied using an aqueouswet-chemical process after all MSVD coating layers have been depositedon the substrate and the MSVD-coated article has exited the MSVD coatingchamber(s). The temporary film can serve as a sacrificial protectivefilm and can be removed from the MSVD-coated article by contact of thearticle's coated surface with water (such as in the washing stepnormally employed in flat glass fabrication processes) prior toinstallation of the coated article in an IG unit or other product. Inthe following discussion, the aesthetic and thermal-managementperformance data pertaining to the present invention is made without thepresence of the temporary film either because the temporary film has notbeen applied, and/or because the temporary film has already beenremoved. Further in the discussion of the thickness of the protectivefilm(s) of the outermost layer, the temporary film is excluded for thereasons discussed.

[0052] With reference to FIG. 2, there is shown an exemplary doubleglazed unit 30 having the coated article 10 (inner pane) incorporatingfeatures of the invention spaced from a sheet 32 (outer pane) by aspacer frame 34. The invention is not limited by the construction andmethod of fabricating the IG unit. For example but not limiting to theinvention, the unit can be one or more of the types disclosed in U.S.Pat. No. 5,655,282. When the IG unit 30 is mounted in a building wall36, the sheet 32 is the outer sheet and the coated article 10 is theinner sheet. Surface 40 of the sheet 32 is the outer surface of theouter sheet or the #1 surface. Surface 42 of the sheet 32 is the innersurface of the outer sheet 32 or the #2 surface. The surface 44 of thesheet 12 is the inner surface of the inner sheet or the #4 surface. Theopposite surface of the sheet 12 is the outer surface of the inner sheet12 and has the coating 14 and is the #3 surface. As can be appreciatedthe invention is not limited to the manner the IG unit is mounted in asash, wall fenestration or any opening of a structure. Further, theglass sheets can be mounted in a sash or window frame, e.g., asdisclosed in PCT/US99/15698.

[0053] The coating of the invention can provide reference IG unit valuesas follows. The “reference IG unit values” or “reference values” arethose values calculated from the measured spectral properties of thecoating for a “reference IG unit” using WINDOW 4.1 fenestration softwareavailable from Lawrence Berkeley National Laboratory. The reference IGunit is defined as a dual pane unit having an outer pane of 6 mmSOLEXIA® glass commercially available from PPG Industries, Inc. and aninner pane of clear glass commercially available from PPG Industries,Inc separated by a distance of 0.5 inch (1.27 cm) by an air gap and withthe coating on the #3 surface.

[0054] SOLEXIA® glass is a subset of tinted glasses and typically hasthe following properties for a nominal 6 mm monolithic piece: a luminoustransmittance of 75% to 80%, a luminous reflectance of 7% to 8% and atotal solar absorption of 46% to 48%. The clear glass typically has aluminous transmittance above 85%, a luminous reflectance of 7% to 9%,and a total solar absorption of 15% to 16%. A clear monolithic piece ofglass having a thickness of about 6 mm has the following properties: aluminous transmittance of above 85%, a luminous reflectance of 7% to 9%,and a total solar absorption of 15% to 16%.

[0055] Unless indicated otherwise, the SOLEXIA® glass referred to in thediscussion of the invention and used in the Examples for a monolithicpiece in the range of 5.5 mm to 6 mm had the following properties: anominal luminous transmittance of 76.8%, a nominal luminous reflectanceof 7.5%, a nominal total solar absorption of 47.2%, a transmitted colorof L*T of 90.4, a*T of −7.40, b*T of 1.16; and reflected color of L*R of33.1, a*R of −2.70, b*R of −0.50. Unless indicated otherwise, the clearglass referred to in the discussion of the invention and used in theExamples for a monolithic piece in the range of 5.5 to 6 mm had thefollowing properties; a nominal luminous transmittance of 88.5%, anominal luminous reflectance of 8.5%, a nominal total solar absorptionof 15.8%, transmitted color of L*T of 95.4, a*T of −1.80, b*T of 0.12;and reflected color of L*R of 35.0, a*R of −0.80, b*R of −1.00.

[0056] The color values herein are those determinable by the CIELAB 1976(L*, a*, b*) system, Illuminant D65, 10 degree observer. Quoted solarproperties correspond to the Lawrence Berkeley National Laboratory'sWINDOW 4.1 wavelength range and integration (trapezoidal) scheme. Theshading coefficient (SC) and solar heat gain coefficient (SHGC) for areference IG unit were calculated under ASHRAE standard assumed summerconditions (exterior environment temperature of 89° F., interiorenvironment temperature of 75° F., wind speed of 7.50 miles/hour(windward directed), solar load of 248.2 Btu/hour-ft², sky temperatureof 89° F., sky emissivity of 1.00). “LSG” is an abbreviation for“Light-to-Solar Gain” ratio and is equal to the ratio of the luminoustransmittance (expressed as a decimal) to the solar heat gaincoefficient (SHGC). As will be appreciated by one skilled in the art,TSET is total solar energy transmitted, TSER1 is total solar energyreflected from the coated surface, and TSER2 is total solar energyreflected from the uncoated surface.

[0057] In one embodiment, the coating 14 can provide reference IG unitvalues (i.e., calculated values for the coating in a reference IG unit)as follows: reference visible light transmittance in the range of 4-0%to 70%, such as 50% to 65%, such as 50% to 60%. The coating can providea reference transmitted color having a transmitted a* (a*T) in the rangeof −5 to −12, such as −7 to −11, such as −8 to −11, such as −9 to −10.The coating can provide a transmitted b* (b*T) in the range of 0 to 5,such as 1 to 5, such as 2 to 5, such as 2.5 to 5, such as 3 to 5, suchas 4 to 5. The coating can provide an exterior visible light reflectance(Rext vis) in the range of greater than 0% to less than 20%, such as 5%to 15%, such as 6% to 11%, such as 8% to 11%, such as 8% to 10%. Thecoating 14 can provide a reference reflected exterior a* (Rexta*) in therange of −2 to −8, such as −2 to −7, such as −3 to −6, such as −3 to −5.The coating can provide a reference reflected exterior b* (Rextb*) inthe range of 0 to −5, such as 0 to −4, such as 0 to −3, such as −1 to−3. The coating can provide a reference shading coefficient in the rangeof 0.25 to 0.45, such as 0.3 to 0.4, such as 0.35 to 0.37, such as lessthan or equal to 0.41, such as less than or equal to 0.37, such as lessthan or equal to 0.36, such as less than or equal to 0.35, such as lessthan or equal to 0.33, such as less than or equal to 0.32, such as lessthan or equal to 0.31. The coating can provide a reference solar heatgain coefficient in the range of 0.2 to 0.4, such as 0.3 to 0.4, such as0.3 to 0.35, such as 0.3 to 0.32, such as than or equal to 0.36, such asless than or equal to 0.35, such as less than or equal to 0.33, such asless than or equal to 0.32, such as less than or equal to 0.31.

[0058] Illustrating the invention are the following Examples which,however, are not to be considered as limiting the invention to theirdetails. All parts and percentages in the following examples, as well asthroughout the specification are by weight unless otherwise indicated.

EXAMPLES

[0059] In the following Examples, the coatings were deposited using anin-line magnetron sputter deposition system Model No. ILS 1600 sold byAirco Temescal on a 6 mm clear glass sheet. Quoted thermal managementperformance values correspond to center-of-glass (COG) values only; edgeeffects due to the spacer and frame are not included. The luminoustransmittance and the luminous exterior reflectance were measured usinga Lamda 9 Spectrophotometer and were determined using the WINDOW 4.1fenestration simulation software, available from Lawrence BerkeleyNational Laboratory (LBNL). Emissivity was determined by measurementsusing an Emissivity Mattson Galaxy 5030 FTIR infrared spectrophotometerin accordance with ASTM E-1585-93 with intervals for infraredintegration over wavelength range of 5-40 microns. Color data referencethe CIELAB 1976 (L*,a*,b*) system, Illuminant D65, 10 degree observer.Quoted solar properties correspond to the Lawrence Berkeley NationalLaboratory's WINDOW 4.1 wavelength range and integration (trapezoidal)scheme. R-Sheet is electrical sheet resistance of the sample's coatedsurface as measured with a four-point probe. The shading coefficient(SC) and solar heat gain coefficient (SHGC) of the IG unit werecalculated under ASHRAE standard assumed summer conditions (exteriorenvironment temperature of 89° F., interior environment temperature of75° F., wind speed of 7.50 miles/hour (windward directed), solar load of248.2 Btu/hour-ft², sky temperature of 89° F., sky emissivity of 1.00).Unless indicated otherwise, the coated glass sheet had a nominalthickness of 6 millimeters (mm). Because the lateral dimensions do nothave any bearing on the COG properties, they are not discussed regardingCOG properties.

[0060] The “IG unit performance” data were calculated from the measuredspectral properties of the coatings for a “reference IG unit” asdescribed above using WINDOW 4.1 fenestration software available fromLawrence Berkeley National Laboratory.

Example 1

[0061] Sample 1 included:

[0062] A first separation layer 22 having a dielectric film of an oxideof an alloy of 54% zinc and 46% tin (by weight) deposited on a clearglass substrate. The dielectric film had physical thickness estimated tobe about 341 Å (34.1 nanometers, nm);

[0063] A first infrared-reflective layer 16 deposited on the firstseparation layer was a metallic silver (Ag) having a physical thicknessof the silver layer estimated to be about 123 Å (12.3 nm);

[0064] A second separation layer 24 included a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 15 Å(1.5 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a dielectric film of an oxide of an alloy of 54% zinc: 46%tin (by weight) having a physical thickness estimated to be about 808 Å(80.8 nm) deposited on the primer film;

[0065] A second infrared-reflective layer 18 was metallic silver (Ag)having a thickness estimated to be about 172 Å (17.2 nm) deposited onthe dielectric film of the second separation layer;

[0066] An outermost separation layer 28 included a primer film ofmetallic titanium (Ti) having a physical thickness of about 15 Å (1.5nm) deposited on the second infrared-reflecting layer, a film of anoxide of an alloy of 54% zinc: 46% tin (by weight) having a physicalthickness estimated to be about 244 Å (24.4 nm), and protective overcoatfilm of an oxide of titanium (Ti) having a physical thickness ofestimated to be about 30 Å (3 nm) deposited on the dielectric film.

[0067] The coated monolithic sheet of sample 1 had the properties, amongothers, detailed in Table 3. TABLE 3 Coated Surface Glass SurfaceReflected Solar Performance Data Sample Transmitted Color Data ReflectedColor Data Color Data TSET TSER1 TSER2 R_(sheet) ID L* a* b* L* a* b* L*a* b* (%) (%) (%) Emissivity (ohms/sq) 1 86.44 −2.41 4.40 45.45 −12.73−4.67 44.39 −11.77 −12.40 30.55 53.45 31.84 0.035 1.9

[0068] The spectrophotometric data of Sample 1 was used as input to theWINDOW 4.1 fenestration simulation software to determine the calculatedreference IG unit performance in Table 4. The designations having a “T”,such as “a*T” refer to the transmitted property and those designationhaving an “R” refer to the reflected property. TABLE 4 IG UnitPerformance Calculated from Spectral Properties solar heat Luminous gainLuminous Exterior shading coefficient, Sample IG unit coatedTransmittance Reflectance coefficient, SC SHGC ID configuration surface(%) a*T b*T (%) a*Rext b*Rext (unitless) (unitless) LSG 1 outer light =#3 53.7 −8.90 4.90 16.5 −13.00 −1.80 0.36 0.31 1.73 6 mm SOLEXIA ®,inner light = 6 mm CLEAR

Example 2

[0069] Sample 2 included:

[0070] A first separation layer 22 having a dielectric film of an oxideof an alloy of 54% zinc: 46% tin (by weight) having a physical thicknessestimated to be about 378 Å (37.8 nm) deposited on a clear glasssubstrate;

[0071] A first infrared-reflecting layer 16 having a metallic silver(Ag) film having a physical thickness estimated to be about 93 Å (9.3nm) deposited on the dielectric film of the first separation layer;

[0072] A second separation layer 24 having a primer film of depositedmetallic titanium (Ti) having a physical thickness estimated to be about15 Å (1.5 nm) deposited on the first infrared-reflecting layer, adielectric film of an oxide of an alloy of 54% zinc: 46% tin (by weight)having a physical thickness of estimated to be about 739 Å (73.9 nm)deposited on the primer film,

[0073] A second infrared-reflective layer 18 having a metallic silver(Ag) having a physical thickness of estimated to be about 114 Å (11.4nm) deposited on the dielectric film of the second separation layer;

[0074] A third separation layer 26 having a primer film deposited asmetallic titanium (Ti) having a physical thickness estimated to be about15 Å (1.5 nm) deposited on the second infrared-reflecting layer 18, anda dielectric film of an oxide of an alloy of 54% zinc: 46% tin (byweight) having a physical thickness estimated to be about 729 Å (72.9nm) deposited on the primer layer of the third separation layer 26;

[0075] A third infrared-reflective layer having a metallic silver (Ag)having a physical thickness estimated to be about 138 Å (13.8 nm)deposited on the dielectric film of the third separation layer, and

[0076] An outermost separation layer 28 having a primer film depositedas metallic titanium (Ti) having a physical thickness estimated to beabout 15 Å (1.5 nm) deposited on the third infrared reflecting layer, adielectric film of an oxide of an alloy of 54% zinc: 46% tin (by weight)having a physical thickness estimated to be about 262 Å (26.2 nm)deposited on the primer layer, and a protective film of an oxide oftitanium (Ti) having a physical thickness estimated to be about 30 Å (3nm) deposited on the dielectric film of the outermost separation layer28;

[0077] Sample 2 had the properties detailed in following Tables 5 and 6.TABLE 5 Coated Surface Glass Surface Reflected Solar Performance DataSample Transmitted Color Data Reflected Color Data Color Data TSET TSER1TSER2 R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity(ohms/sq) 2 84.49 −2.29 8.15 49.83 −14.85 −10.77 48.16 −16.09 −19.3425.64 60.65 37.34 0.031 1.8

[0078] TABLE 6 IG Unit Performance Calculated from Spectral Propertiesof Example 2 solar heat Luminous gain Luminous Exterior shadingcoefficient, Sample IG unit coated Transmittance Reflectancecoefficient, SC SHGC ID configuration surface (%) a*T b*T (%) a*Rextb*Rext (unitless) (unitless) LSG Example 2 outer light = #3 51.0 −8.608.14 18.4 −16.00 −5.50 0.33 0.28 1.82 6 mm SOLEXIA ®, inner light = 6 mmCLEAR

Example 3

[0079] Sample 3 included:

[0080] A first separation layer 22 having a dielectric film of an oxideof an alloy of 54% zinc: 46% tin (by weight) deposited on the glasssubstrate. The dielectric film had physical thickness estimated to beabout 336 Å (33.6 nanometers, nm);

[0081] A first infrared-reflective layer 16 deposited on the firstseparation layer was a metallic silver (Ag) having a physical thicknessof the silver layer estimated to be about 111 Å (11.1 nm);

[0082] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 15 Å(1.5 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a dielectric film of an oxide of an alloy of 54% zinc: 46%tin (by weight) having a physical thickness estimated to be about 842 Å(84.2 nm) deposited on the primer film;

[0083] A second infrared-reflective layer 18 was metallic silver (Ag)having a thickness estimated to be about 161 Å (16.1 nm) deposited onthe dielectric film of the second separation layer;

[0084] An outermost separation layer 28 included a primer film ofmetallic titanium (Ti) having a physical thickness of about 15 Å (1.5nm) deposited on the second infrared-reflecting layer, a film of anoxide of an alloy of 54% zinc: 46% tin (by weight) having a physicalthickness estimated to be about 245 Å (24.5 nm), and protective film ofan oxide of titanium (Ti) having a physical thickness of estimated to beabout 30 Å (3 nm) deposited on the dielectric film.

[0085] Sample 3 had properties as detailed in Tables 7 and 8. TABLE 7Coated Surface Glass Surface Reflected Solar Performance Data SampleTransmitted Color Data Reflected Color Data Color Data TSET TSER1 TSER2R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq)3 85.85 −2.63 1.03 42.76 −12.80 1.40 41.50 −15.49 −7.00 29.24 54.1829.60 0.033 2.26

[0086] TABLE 8 IG Unit Performance Calculated from Spectral Propertiesof Example 3. solar heat Luminous gain Luminous Exterior shadingcoefficient, Sample IG unit coated Transmittance Reflectancecoefficient, SC SHGC ID configuration surface (%) A*T B*T (%) a*Rextb*Rext (unitless) (unitless) LSG 3 outer light = #3 52.6 −8.90 2.05 15.4−13.00 1.18 0.36 0.31 1.70 6 mm SOLEXIA ®, inner light = 6 mm CLEAR

Example 4

[0087] Sample 4 included:

[0088] A first separation layer 22 having a dielectric film of an oxideof an alloy of 54% zinc: 46% tin (by weight) deposited on the glasssubstrate. The dielectric film had physical thickness estimated to beabout 293 Å (29.3 nanometers, nm);

[0089] A first infrared-reflective layer 16 of metallic silver (Ag)deposited on the first separation layer having a physical thickness ofthe silver layer estimated to be about 113 Å (11.3 nm);

[0090] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 15 Å(1.5 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a dielectric film of an oxide of an alloy of 54% zinc: 46%tin (by weight) having a physical thickness estimated to be about 851 Å(85.1 nm) deposited on the primer film;

[0091] A second infrared-reflective layer 18 of metallic silver (Ag)having a thickness estimated to be about 197 Å (19.7 nm) deposited onthe dielectric film of the second separation layer;

[0092] An outermost separation layer 28 having a primer film of metallictitanium (Ti) having a physical thickness of about 15 Å (1.5 nm)deposited on the second infrared-reflecting layer, a film of an oxide ofan alloy of 54% zinc: 46% tin (by weight) having a physical thicknessestimated to be about 245 Å (24.5 nm), and protective overcoat film ofan oxide of titanium (Ti) having a physical thickness of estimated to beabout 30 Å (3 nm) deposited on the dielectric film.

[0093] Sample 4 had properties detailed in Tables 9 and 10. TABLE 9Coated Surface Glass Surface Reflected Solar Performance Data SampleTransmitted Color Data Reflected Color Data Color Data TSET TSER1 TSER2R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq)4 83.34 −3.63 2.43 51.22 −7.65 1.27 48.20 −15.21 −11.49 25.26 60.9732.76 0.031 1.89

[0094] TABLE 10 IG Unit Performance Calculated from Spectral Propertiesof Sample 4 solar heat Luminous gain Luminous Exterior shadingcoefficient, Sample IG unit coated Transmittance Reflectancecoefficient, SC SHGC ID configuration surface (%) a*T b*T (%) a*Rextb*Rext (unitless) (unitless) LSG 4 outer light = #3 49.1 −9.60 3.30 19.2−12.00 1.28 0.33 0.28 1.75 6 mm SOLEXIA ®, inner light = 6 mm CLEAR

Example 5

[0095] Sample 5 included:

[0096] A first separation layer 22 having a dielectric film of an oxideof an alloy of 54% zinc: 46% tin (by weight) deposited on a 2.3millimeter thick clear glass substrate having a thickness of 2.5 mm. Thedielectric film had physical thickness estimated to be about 319 Å (31.9nanometers, nm);

[0097] A first infrared-reflective layer 16 of a metallic silver (Ag)deposited on the first separation layer had a physical thicknessestimated to be about 114 Å (11.4 nm);

[0098] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 15 Å(1.5 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a dielectric film of an oxide of an alloy of 54% zinc: 46%tin (by weight) having a physical thickness estimated to be about 845 Å(84.5 nm) deposited on the primer film;

[0099] A second infrared-reflective layer 18 having metallic silver (Ag)having a thickness estimated to be about 170 Å (17.0 nm) deposited onthe dielectric film of the second separation layer;

[0100] An outermost separation layer 28 having a primer film of metallictitanium (Ti) having a physical thickness of about 15 Å (1.5 nm)deposited on the second infrared-reflecting layer, a film of an oxide ofan alloy of 54% zinc: 46% tin (by weight) having a physical thicknessestimated to be about 257 Å (25.7 nm), and protective overcoat film ofan oxide of titanium (Ti) having a physical thickness of estimated to beabout 30 Å (3 nm) deposited on the dielectric film.

[0101] Sample 5 had properties shown on Tables 11 and 12. TABLE 11Coated Surface Glass Surface Reflected Solar Performance Data SampleTransmitted Color Data Reflected Color Data Color Data TSET TSER1 TSER2R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq)5 87.59 −2.54 2.01 41.74 −10.82 −1.92 40.98 −12.68 −11.60 30.48 55.5742.20 0.035 2.06

[0102] TABLE 12 IG Unit Performance Calculated from Spectral Propertiessolar heat Luminous gain Luminous Exterior shading coefficient, SampleIG unit coated Transmittance Reflectance coefficient, SC SHGC IDconfiguration surface (%) a*T b*T (%) a*Rext b*Rext (unitless)(unitless) LSG 5 outer light = #3 55.3 −8.90 2.88 14.9 −12.00 −0.60 0.360.31 1.78 6 mm SOLEXIA ®, inner light = 2.3 mm CLEAR

Example 6

[0103] Sample 6 included:

[0104] A first separation layer 22 having included a first dielectricfilm of an oxide of an alloy of 54% zinc: 46% tin (by weight) depositedon a glass substrate having a thickness of about 2.3 millimeters; thedielectric film had physical thickness estimated to be about 240 Å (24.0nanometers, nm), a second dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the first dielectric layer; thesecond dielectric film had physical thickness estimated to be about 80 Å(8.0 nanometers, nm) providing dielectric films having a combinedthickness of 320 Å (32.0 nm);

[0105] A first infrared-reflective layer 16 of metallic silver (Ag)deposited on the first separation layer having a physical thicknessestimated to be about 114 Å (11.4 nm);

[0106] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 25 Å(2.5 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a first dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the primer film of the secondseparation layer; the first dielectric film had physical thicknessestimated to be about 84 Å (8.4 nanometers, nm) a second dielectric filmof an oxide of an alloy of 54% zinc: 46% tin (by weight) deposited onthe first dielectric film; the second dielectric film had physicalthickness estimated to be about 676 Å (67.6 nanometers, nm), a thirddielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the second dielectric layer; the third dielectric film hadphysical thickness estimated to be about 84 Å (8.4 nanometers, nm)providing three dielectric films having a combined physical thicknessestimated to be about 844 Å (84.4 nm);

[0107] A second infrared-reflective layer 18 of metallic silver (Ag)having a thickness estimated to be about 170 Å (17.0 nm) deposited onthe third dielectric film of the second separation layer;

[0108] An outermost separation layer 28 having a primer film of metallictitanium (Ti) having a physical thickness of about 25 Å (2.5 nm)deposited on the second infrared-reflecting layer, a first dielectricfilm of an oxide of an alloy of 90% zinc: 10% tin (by weight) depositedon the primer film of the outermost separation layer; the firstdielectric film had physical thickness estimated to be about 85 Å (8.5nanometers, nm), a second dielectric film of an oxide of an alloy of 54%zinc: 46% tin (by weight) deposited on the first dielectric film; thesecond dielectric film had physical thickness estimated to be about 172Å (17.2 nanometers, nm), the first and second dielectric films having acombined physical thickness estimated to be about 257 Å (25.7 nm), and aprotective overcoat film of an oxide of titanium (Ti) having a physicalthickness of estimated to be about 30 Å (3 nm) deposited on thedielectric film.

[0109] The piece of the monolithic coated glass of Sample 6, havinglateral dimensions of approximately 4 inch×4 inch and nominal thicknessof 2.3 millimeters, had properties as detailed in Tables 13 and 14 afterit was heated in a box oven (1300° F. oven temperature setpoint) forapproximately 3 minutes, then removed from the oven and subsequentlyallowed to cool to room temperature in ambient air. The lateraldimensions of Sample 6 were presented because the sample washeat-treated and the dimensions are of interest.

[0110] Sample 6 had properties shown on Tables 13 and 14. TABLE 13Coated Surface Glass Surface Reflected Solar Performance Data SampleTransmitted Color Data Reflected Color Data Color Data TSET TSER1 TSER2R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq)6 (after 89.60 −0.79 3.93 41.41 −12.04 0.80 39.83 −9.51 −10.76 33.1156.28 44.54 0.029 1.26 heating)

[0111] TABLE 14 IG Unit Performance Calculated from Spectral Propertiesof Example 6 (after heating) solar heat Luminous gain Luminous Exteriorshading coefficient, Sample IG unit coated Transmittance Reflectancecoefficient, SC SHGC ID configuration surface (%) a*T b*T (%) a*Rextb*Rext (unitless) (unitless) LSG 6 (after outer light = #3 58.8 −7.504.64 14.9 −12.00 0.90 0.36 0.31 1.90 heating) 6 mm SOLEXIA ®, innerlight = 2.3 mm CLEAR

Example 7

[0112] Sample 7 included:

[0113] A first separation layer 22 having a first dielectric film of anoxide of an alloy of 54% zinc: 46% tin (by weight) deposited on a 4×4inch 2.3 mm glass substrate; the dielectric film had physical thicknessestimated to be about 302 Å (30.2 nanometers, nm), a second dielectricfilm of an oxide of an alloy of 90% zinc: 10% tin (by weight) depositedon the first dielectric layer; the second dielectric film had physicalthickness estimated to be about 75 Å (7.5 nanometers, nm) providingdielectric films having a combined physical thickness estimated to be377 Å (37.7 nm);

[0114] A first infrared-reflective layer 16 deposited on the firstseparation layer was a metallic silver (Ag) having a physical thicknessof the silver layer estimated to be about 93 Å (9.3 nm);

[0115] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 25 Å(2.5 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a first dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the primer film of the secondseparation layer; the first dielectric film had physical thicknessestimated to be about 74 Å (7.4 nanometers, nm) a second dielectric filmof an oxide of an alloy of 54% zinc: 46% tin (by weight) deposited onthe first dielectric film; the second dielectric film had physicalthickness estimated to be about 591 Å (59.1 nanometers, nm), a thirddielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the second dielectric layer; the third dielectric film hadphysical thickness estimated to be about 74 Å (7.4 nanometers, nm)providing three dielectric films having a combined physical thicknessestimated to be about 739 Å (73.9 nm);

[0116] A second infrared-reflective layer 18 was metallic silver (Ag)having a thickness estimated to be about 114 Å (11.4 nm) deposited onthe third dielectric film of the second separation layer;

[0117] A third separation layer 26 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 25 Å(2.5 nm) deposited on the silver film of the second infrared-reflectivelayer 18 and a first dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the primer film of the secondseparation layer; the first dielectric film had physical thicknessestimated to be about 73 Å (7.3 nanometers, nm) a second dielectric filmof an oxide of an alloy of 54% zinc: 46% tin (by weight) deposited onthe first dielectric film; the second dielectric film had physicalthickness estimated to be about 583 Å (58.3 nanometers, nm), a thirddielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the second dielectric layer; the third dielectric film hadphysical thickness estimated to be about 73 Å (7.3 nanometers, nm)providing three dielectric films having a combined physical thicknessestimated to be about 729 Å (72.9 nm);

[0118] A third infrared-reflective layer 20 was metallic silver (Ag)having a thickness estimated to be about 138 Å (13.8 nm) deposited onthe third dielectric film of the third separation layer 26;

[0119] An outermost separation layer 28 having a primer film of metallictitanium (Ti) having a physical thickness of about 25 Å (2.5 nm)deposited on the third infrared-reflecting layer, a first dielectricfilm of an oxide of an alloy of 90% zinc: 10% tin (by weight) depositedon the primer film of the outermost separation layer; the firstdielectric film had physical thickness estimated to be about 87 Å (8.7nanometers, nm), a second dielectric film of an oxide of an alloy of 54%zinc: 46% tin (by weight) deposited on the first dielectric film; thesecond dielectric film had physical thickness estimated to be about 175Å (17.5 nanometers, nm), the first and second dielectric films having acombined physical thickness estimated to be about 262 Å (26.2 nm), and aprotective overcoat film of an oxide of titanium (Ti) having a physicalthickness of estimated to be about 30 Å (3 nm) deposited on thedielectric film.

[0120] Sample 7 had properties detailed in Tables 15 and 16 after it washeated in a box oven (1300° F. oven temperature setpoint) forapproximately 3 minutes, then removed from the oven and allowed to coolto room temperature in ambient air: TABLE 15 Coated Surface GlassSurface Reflected Solar Performance Data Sample Transmitted Color DataReflected Color Data Color Data TSET TSER1 TSER2 R_(sheet) ID L* a* b*L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq) 7 (after 90.13 −3.322.78 26.33 6.46 0.39 28.22 4.00 −1.85 32.59 53.28 40.66 0.027 1.13heating)

[0121] TABLE 16 IG Unit Performance Calculated from Spectral Propertiesof Example 7 after heating solar heat Luminous gain Luminous Exteriorshading coefficient, Sample IG unit coated Transmittance Reflectancecoefficient, SC SHGC ID configuration surface (%) a*T b*T (%) a*Rextb*Rext (unitless) (unitless) LSG 7 (after outer light = #3 59.2 −9.603.66 10.5 −1.80 −0.10 0.38 0.33 1.79 heating 6 mm SOLEXIA ®, inner light= 2.3 mm CLEAR

Example 8

[0122] Sample 8 included:

[0123] A first separation layer 22 having a first dielectric film of anoxide of an alloy of 54% zinc: 46% tin (by weight) deposited on a glasssubstrate having a thickness of about 6 millimeters; the dielectric filmhad physical thickness estimated to be about 257 Å (25.7 nanometers,nm), a second dielectric film of an oxide of an alloy of 90% zinc: 10%tin (by weight) deposited on the first dielectric layer; the seconddielectric film had physical thickness estimated to be about 64 Å (6.4nanometers, nm) providing dielectric films having a combined physicalestimated thickness of 321 Å (32.1 nm);

[0124] A first infrared-reflective layer 16 having a metallic silver(Ag) having a physical thickness of the silver layer estimated to beabout 119 Å (11.9 nm) deposited on the first separation layer was;

[0125] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 20 Å(2.0 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a first dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the primer film of the secondseparation layer; the first dielectric film had physical thicknessestimated to be about 92 Å (9.2 nanometers, nm), a second dielectricfilm of an oxide of an alloy of 54% zinc: 46% tin (by weight) depositedon the first dielectric film; the second dielectric film had physicalthickness estimated to be about 632 Å (63.2 nanometers, nm), a thirddielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the second dielectric layer; the third dielectric film hadphysical thickness estimated to be about 108 Å (10.8 nanometers, nm)providing three dielectric films having a combined physical thicknessestimated to be about 832 Å (83.2 nm);

[0126] A second infrared-reflective layer 18 having a metallic silver(Ag) film having a thickness estimated to be about 176 Å (17.6 nm)deposited on the third dielectric film of the second separation layer;

[0127] An outermost separation layer 28 having a primer film of metallictitanium (Ti) having a physical thickness of about 20 Å (2.0 nm)deposited on the second infrared-reflecting layer, a first dielectricfilm of an oxide of an alloy of 90% zinc: 10% tin (by weight) depositedon the primer film of the outermost separation layer; the firstdielectric film had physical thickness estimated to be about 72 Å (7.2nanometers, nm), a second dielectric film of an oxide of an alloy of 54%zinc: 46% tin (by weight) deposited on the first dielectric film; thesecond dielectric film had physical thickness estimated to be about 134Å (13.4 nanometers, nm), the first and second dielectric films having acombined physical thickness estimated to be about 206 Å (20.6 nm), and aprotective overcoat film of an oxide of titanium (Ti) having a physicalthickness of estimated to be about 44 Å (4.4 nm) deposited on thedielectric film.

[0128] Sample 8 had the properties in Tables 17 and 18. TABLE 17 CoatedSurface Glass Surface Reflected Solar Performance Data SampleTransmitted Color Data Reflected Color Data Color Data TSET TSER1 TSER2R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq)8 87.50 −2.94 4.68 41.67 −9.28 −2.29 41.34 −10.49 −13.35 29.62 56.7033.78 0.031 1.55

[0129] TABLE 18 IG Unit Performance Calculated from Spectral Propertiesof Sample 8 solar heat Luminous gain Luminous Exterior shadingcoefficient, Sample IG unit coated Transmittance Reflectancecoefficient, SC SHGC ID configuration surface (%) a*T b*T (%) a*Rextb*Rext (unitless) (unitless) LSG 8 outer light = #3 55.3 −9.20 5.25 14.9−11.00 −0.70 0.36 0.31 1.78 6 mm SOLEXIA ®, inner light = 6 mm CLEAR

Example 9

[0130] Sample 9 included:

[0131] A first separation layer 22 having a first dielectric film of anoxide of an alloy of 54% zinc: 46% tin (by weight) deposited on a glasssubstrate having a thickness of about 6 millimeters; the dielectric filmhad physical thickness estimated to be about 286 Å (28.6 nanometers,nm), a second dielectric film of an oxide of an alloy of 90% zinc: 10%tin (by weight) deposited on the first dielectric layer; the seconddielectric film had physical thickness estimated to be about 67 Å (6.7nanometers, nm) providing dielectric films having a combined physicalestimated thickness of 353 Å (35.3 nm);

[0132] A first infrared-reflective layer 16 having a metallic silver(Ag) having a physical thickness of the silver layer estimated to beabout 109 Å (10.9 nm) deposited on the first separation layer;

[0133] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 20 Å(2.0 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a first dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the primer film of the secondseparation layer; the first dielectric film had physical thicknessestimated to be about 94 Å (9.4 nanometers, nm), a second dielectricfilm of an oxide of an alloy of 54% zinc: 46% tin (by weight) depositedon the first dielectric film; the second dielectric film had physicalthickness estimated to be about 648 Å (64.8 nanometers, nm), a thirddielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the second dielectric layer; the third dielectric film hadphysical thickness estimated to be about 111 Å (1.11 nanometers, nm)providing three dielectric films having a combined physical thicknessestimated to be about 852 Å (85.2 nm);

[0134] A second infrared-reflective layer 18 having metallic silver (Ag)having a thickness estimated to be about 182 Å (18.2 nm) deposited onthe third dielectric film of the second separation layer;

[0135] An outermost separation layer 28 included a primer film ofmetallic titanium (Ti) having a physical thickness of about 20 Å (2.0nm) deposited on the second infrared-reflecting layer, a firstdielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the primer film of the outermost separation layer; thefirst dielectric film had physical thickness estimated to be about 75 Å(7.5 nanometers, nm), a second dielectric film of an oxide of an alloyof 54% zinc: 46% tin (by weight) deposited on the first dielectric film;the second dielectric film had physical thickness estimated to be about139 Å (13.9 nanometers, nm), the first and second dielectric filmshaving a combined physical thickness estimated to be about 214 Å (21.4nm), and a protective overcoat film of an oxide of titanium (Ti) havinga physical thickness of estimated to be about 44 Å (4.4 nm) deposited onthe dielectric film.

[0136] Sample 9 had the properties detailed in Tables 19 and 20. TABLE19 Coated Surface Glass Surface Reflected Solar Performance Data SampleTransmitted Color Data Reflected Color Data Color Data TSET TSER1 TSER2R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq)9 87.23 −4.36 5.11 44.35 −1.44 −1.32 43.52 −5.60 −12.58 29.55 57.6533.88 0.025 1.58

[0137] TABLE 20 IG Unit Performance Calculated from Spectral Propertiesof Sample 9 solar heat Luminous gain Luminous Exterior shadingcoefficient, Sample IG unit coated Transmittance Reflectancecoefficient, SC SHGC ID configuration surface (%) a*T b*T (%) a*Rextb*Rext (unitless) (unitless) LSG 9 outer light = #3 54.9 −10.00 5.6616.0 −7.20 −0.20 0.35 0.30 1.83 6 mm SOLEXIA ®, inner light = 6 mm CLEAR

Example 10

[0138] Sample 10 included:

[0139] A first separation layer 22 having a first dielectric film of anoxide of an alloy of 54% zinc: 46% tin (by weight) deposited on a glasssubstrate having a thickness of about 6 millimeters; the dielectric filmhad physical thickness estimated to be about 390 Å (39.0 nanometers,nm), a second dielectric film of an oxide of an alloy of 90% zinc: 10%tin (by weight) deposited on the first dielectric layer; the seconddielectric film had physical thickness estimated to be about 104 Å (10.4nanometers, nm) providing dielectric films having a combined physicalestimated thickness of 494 Å (49.4 nm);

[0140] A first infrared-reflective layer 16 having a metallic silver(Ag) having a physical thickness of the silver layer estimated to beabout 106 Å (10.6 nm) deposited on the first separation layer;

[0141] A second separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 20 Å(2.0 nm) deposited on the silver film of the first infrared-reflectivelayer 16 and a first dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the primer film of the secondseparation layer; the first dielectric film had physical thicknessestimated to be about 97 Å (9.7 nanometers, nm), a second dielectricfilm of an oxide of an alloy of 54% zinc: 46% tin (by weight) depositedon the first dielectric film; the second dielectric film had physicalthickness estimated to be about 551 Å (55.1 nanometers, nm), a thirddielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the second dielectric layer; the third dielectric film hadphysical thickness estimated to be about 97 Å (9.7 nanometers, nm)providing three dielectric films having a combined physical thicknessestimated to be about 744 Å (74.4 nm);

[0142] A second infrared-reflective layer 18 having a metallic silver(Ag) having a thickness estimated to be about 124 Å (12.4 nm) depositedon the third dielectric film of the second separation layer;

[0143] A third separation layer 24 having a primer film of metallictitanium (Ti) having a physical thickness estimated to be about 20 Å(2.0 nm) deposited on the silver film of the first infrared-reflectivelayer 18 and a first dielectric film of an oxide of an alloy of 90%zinc: 10% tin (by weight) deposited on the primer film of the secondseparation layer; the first dielectric film had physical thicknessestimated to be about 99 Å (9.9 nanometers, nm), and a second dielectricfilm of an oxide of an alloy of 54% zinc: 46% tin (by weight) depositedon the first dielectric film; the second dielectric film had physicalthickness estimated to be about 565 Å (56.5 nanometers, nm) a thirddielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the second dielectric layer; the third dielectric film hadphysical thickness estimated to be about 99 Å (9.9 nanometers, nm)providing three dielectric films having a combined physical thicknessestimated to be about 764 Å (76.4 nm);

[0144] A third infrared-reflective layer 20 was metallic silver (Ag)having a thickness estimated to be about 181 Å (18.1 nm) deposited onthe third dielectric film of the third separation layer.

[0145] An outermost separation layer 28 included a primer film ofmetallic titanium (Ti) having a physical thickness of about 20 Å (2.0nm) deposited on the second infrared-reflecting layer, a firstdielectric film of an oxide of an alloy of 90% zinc: 10% tin (by weight)deposited on the primer film of the outermost separation layer; thefirst dielectric film had physical thickness estimated to be about 93 Å(9.3 nanometers, nm), a second dielectric film of an oxide of an alloyof 54% zinc: 46% tin (by weight) deposited on the first dielectric film;the second dielectric film had physical thickness estimated to be about217 Å (21.7 nanometers, nm), the first and second dielectric filmshaving a combined physical thickness estimated to be about 310 Å (31.0nm), and a protective overcoat film of an oxide of titanium (Ti) havinga physical thickness of estimated to be about 46 Å (4.6 nm) deposited onthe dielectric film.

[0146] Sample 10 had the properties detailed in Tables 21 and 22. TABLE21 Coated Surface Glass Surface Reflected Solar Performance Data SampleTransmitted Color Data Reflected Color Data Color Data TSET TSER1 TSER2R_(sheet) ID L* a* b* L* a* b* L* a* b* (%) (%) (%) Emissivity (ohms/sq)10 85.57 −4.44 1.94 34.05 −1.93 0.47 37.35 −6.00 −1.96 25.17 57.82 33.050.026 1.06

[0147] TABLE 22 IG Unit Performance Calculated from Spectral Propertiesof Sample 10 on 6 mm Clear Glass Substrate solar heat Luminous gainLuminous Exterior shading coefficient, Sample IG unit coatedTransmittance Reflectance coefficient, SC SHGC ID configuration surface(%) a*T b*T (%) a*Rext b*Rext (unitless) (unitless) LSG 10 outer light =#3 51.9 −10.00 2.85 12.5 −5.70 0.64 0.35 0.30 1.73 SOLEXIA ®, innerlight = CLEAR

Example 11

[0148] Samples 11-13 had the layer structures shown in Table 23 belowand were deposited on a 6 mm clear glass sheet. TABLE 23 ZnO Zn₂SnO₄ ZnOZn₂SnO₄ ZnO “bottom “bottom “bottom basecoat basecoat bottom bottomcentercoat” centercoat” centercoat” center center component component AgTi primer component component component Ag Ti primer Sample # (nm) (nm)(nm) (nm) (nm) (nm) (nm) (nm) (nm) 11 33.0 14.6 12.2 1.1 12.1 49.3 12.113.9 1.2 12 32.3 16.1 12.4 2.1 11.4 49.2 12.1 14.3 2.2 13 29.1 13.7 12.21.1 12.1 49.3 12.1 13.9 1.2 ZnO Zn₂SnO₄ ZnO “top “top “top ZnO Zn₂SnO₄centercoat” centercoat” centercoat” top top Topcoat Topcoat TiO₂component component component Ag Ti primer component Component OvercoatSample # (nm) (nm) (nm) (nm) (nm) (nm) (nm) (nm) 11 11.2 51.1 11.5 16.91.1 10.8 21.4 3.7 12 10.7 50.7 11.1 16.4 1.9 10.3 21.2 3.4 13 10.8 50.411.5 16.7 1.1 10.0 21.4 3.7

[0149] Samples 11-13 provided the spectral properties shown in Tables 24for a coated sheet. The calculated reference IG unit performance forSamples 11-13 is shown in Table 25. TABLE 24 Solar Performance Data**TSET, TSER2, Coated Surface Glass Surface total solar TSER1, total totalsolar Transmitted Reflected Reflected energy solar reflectancereflectance Rsheet Color Data* Color Data* Color Data* transmittancefrom coated from uncoated (ohms/ Sample # L* T a* T b* T L* T a* R b* RL* R a* R b* R (%) surface (%) glass surface (%) Emissivity square) 1187.23 −4.67 2.62 27.21 −4.82 −5.52 32.97 −4.35 −4.17 26.66 55.69 35.340.030 1.18 12 89.79 −2.86 1.93 27.21 −5.20 −5.00 31.99 −5.19 −3.96 29.3756.88 35.29 0.012 0.85 13 87.36 −5.10 1.73 24.69 −2.16 −2.13 31.03 −2.93−1.33 26.69 55.58 35.18 0.031 1.19

[0150] TABLE 25 Rext_vis Sample # Tvis (%) a*T b*T (%) Rext_a* Rext_b*SC SHGC LSG Ratio 11 54.4 −11.00 3.45 10.6 −6.10 −2.00 0.36 0.31 1.74 1258.7 −9.20 2.90 10.6 −6.40 −2.00 0.36 0.31 1.88 13 54.6 −11.00 2.71 10.1−4.90 −1.00 0.37 0.32 1.73

[0151] As can be appreciated, other aesthetics and solar performance canbe achieved using the aforementioned general coating stack design. Forexample IG units can be made using the coatings of the invention withvaries types of glasses. For example, and not limiting to the inventionhaving a glass that limits the transmission of ultraviolet energysimilar to the type sold by PPG Industries, Inc. under the trademarkSolargreen; a blue tint glass e.g. of the type sold by PPG IndustriesInc. under the trademark Azurlite; a glass having low transmission e.g.of the type sold by PPG Industries inc under the trademark Solarbronze;and of the type sold by Pilkington-LOF under the trademark BlueGreen.

[0152] As can be appreciated, the aforementioned discussion and Examplesare only meant to illustrate embodiments of the invention, and that theinvention is not limited thereto.

What is claimed is:
 1. A coated article for use in an IG unit,comprising; a substrate; and a coating formed over at least a portion ofthe substrate, wherein the coating comprises: a first separation layercomprising at least one dielectric layer; a first infrared reflectivelayer deposited over the first separation layer; a second separationlayer comprising at least one dielectric layer deposited over the firstinfrared reflective layer; a second infrared reflective layer depositedover the second separation layer; a third separation layer comprising atleast one dielectric layer deposited over the second infrared reflectivelayer; and a third infrared reflective layer deposited over the thirdseparation layer, wherein the coating is identified for a position onthe #2 or #3 surface of the IG unit after being mounted.
 2. The articleaccording to claim 1, wherein the coating is on the #3 surface.
 3. Thearticle according to claim 1, wherein the separation layers include atleast one material selected from the group consisting of metal oxides,oxides of metal alloys, doped metal oxides, nitrides, oxynitrides, andmixtures thereof.
 4. The article of claim 3, wherein the separationlayers include at least one metal oxide selected from the groupconsisting of oxides of zinc, titanium, hafnium, zirconium, niobium,bismuth, indium, tin, and mixtures thereof.
 5. The article of claim 1,wherein at least one of the dielectric layers comprises a plurality ofdielectric films.
 6. The article of claim 1, wherein the infraredreflective layers include at least one metal selected from the groupconsisting of gold, copper, silver, or mixtures, alloys, or combinationsthereof.
 7. The article of claim 1, wherein the first separation layercomprises a zinc oxide layer deposited over a zinc stannate layer. 8.The article of claim 7, wherein the zinc oxide layer has a thickness inthe range of 100 Å to 200 Å.
 9. The article of claim 7, wherein the zincstannate layer has a thickness in the range of 250 Å to 400 Å.
 10. Thearticle of claim 1, wherein the first infrared reflective layer has athickness in the range of 100 Å to 150 Å.
 11. The article of claim 1,wherein the second separation layer comprises a first zinc oxide layer,a zinc stannate layer deposited over the first zinc oxide layer, and asecond zinc oxide layer deposited over the zinc stannate layer.
 12. Thearticle of claim 11, wherein the first zinc oxide layer has a thicknessin the range of 100 Å to 150 Å, the zinc stannate layer has a thicknessin the range of 200 Å to 500 Å, and the second zinc oxide layer has athickness in the range of 100 Å to 150 Å.
 13. The article of claim 1,wherein the second infrared reflective layer has a thickness in therange of 100 Å to 150 Å.
 14. The article of claim 1, wherein the thirdseparation layer comprises a first zinc oxide layer, a zinc stannatelayer deposited over the first zinc oxide layer, and a second zinc oxidelayer deposited over the zinc stannate layer.
 15. The article of claim14, wherein the zinc oxide layers each have a thickness in the range of100 Å to 150 Å.
 16. The article of claim 15, wherein the zinc stannatelayer has a thickness in the range of 450 Å to 550 Å.
 17. The article ofclaim 1, wherein the third infrared reflective layer has a thickness inthe range of 140 Å to 180 Å.
 18. The article of claim 1, including afourth separation layer comprising at least one dielectric layerdeposited over the third infrared reflective layer.
 19. The article ofclaim 18, wherein the fourth layer comprises a zinc stannate layerdeposited over a zinc oxide layer.
 20. The article of claim 19, whereinthe zinc stannate layer has a thickness in the range of 150 Å to 250 Å.21. The article of claim 19, wherein the zinc oxide layer has athickness in the range of 80 Å to 120 Å.
 22. The article of claim 18,including a protective overcoat deposited over the fourth separationlayer and comprising titania having a thickness in the range of 20 Å to50 Å.
 23. An IG unit having the article of claim
 1. 24. A coated articlefor use in an IG unit, comprising: a substrate; and a coating formedover at least a portion of the substrate, wherein the coating comprises:a first separation layer comprising at least one dielectric layer; afirst infrared reflective layer formed over the first separation layer;a second separation layer comprising at least one dielectric layerformed over the first infrared reflective layer; and a second infraredreflective layer formed over the second separation layer, wherein thecoating is identified for a position on the #2 or #3 surface of the IGunit after being mounted, and wherein the coating provides a referencesolar heat gain coefficient of less than or equal to 0.36.
 25. Thecoated article of claim 24, wherein the coating provides a referencesolar heat gain coefficient of less than or equal to 0.32.
 26. Thecoated article of claim 24, wherein the coating is identified for aposition on the #3 surface.
 27. An IG unit having the article of claim24.
 28. An IG unit, comprising: a first pane defining a #1 and a #2surface; at least one second pane defining a #3 and a #4 surface; and acoating formed over at least a portion of the #2 or #3 surface, whereinthe coating comprises: a first separation layer comprising at least onedielectric layer; a first infrared reflective layer deposited over thefirst separation layer; a second separation layer comprising at leastone dielectric layer deposited over the first infrared reflective layer;a second infrared reflective layer deposited over the second separationlayer; a third separation layer comprising at least one dielectric layerdeposited over the second infrared reflective layer; and a thirdinfrared reflective layer deposited over the third separation layer. 29.The IG unit of claim 28, having a reference visible light transmittancein the range of 50% to 60%.
 30. The IG unit of claim 28, having areference transmitted a* (a*T) in the range of −5 to −12.
 31. The IGunit of claim 28, having a reference transmitted b* (b*T) in the rangeof 0 to
 5. 32. The IG unit of claim 28, having a reference exteriorvisible light reflectance (Rext vis) in the range of 5% to 15%.
 33. TheIG unit of claim 28, having a reference reflected exterior a* (Rexta*)in the range of −2 to −10.
 34. The IG unit of claim 28, having areference reflected exterior b* (Rextb*) in the range of −0 to −5. 35.The IG unit of claim 28, having a reference shading coefficient of lessthan 0.41.
 36. The IG unit of claim 28, having a reference solar heatgain coefficient of less than 0.36.
 37. The IG unit of claim 28, whereinthe coating is formed on the #3 surface.
 38. An IG unit, comprising: afirst pane defining a #1 and a #2 surface; at least one second panedefining a #3 and a #4 surface; and a coating formed over at least aportion of the #2 or #3 surface, the coating comprising: a firstseparation layer comprising at least one dielectric layer; a firstinfrared reflective layer deposited over the first separation layer; asecond separation layer comprising at least one dielectric layerdeposited over the first infrared reflective layer; and a secondinfrared reflective layer deposited over the second separation layer,wherein the coating provides a reference solar heat gain coefficient ofless than or equal to 0.36.
 39. The IG unit of claim 38, wherein thecoating provides a reference solar heat gain coefficient of less than orequal to 0.32.
 40. The IG unit of claim 38, wherein the coating is onthe #3 surface.